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E-type Asteroids (Tholen)
E-type (enstatite achondrite–type) asteroids are asteroids thought to have enstatite (MgSiO3) achondrite surfaces. They form a large proportion of asteroids inward of the asteroid belt known as Hungaria asteroids, but rapidly become very rare as the asteroid belt proper is entered. Some are quite far from the inner edge of the asteroid belt, such as 64 Angelina. They are thought to have originated from the highly reduced mantle of a differentiated asteroid. Description E-type asteroids have a high albedo (0.3 or higher), which distinguishes them from the more common M-type asteroid, M-type asteroids. Their electromagnetic spectrum, spectrum is featureless flat to reddish. Probably because they originated from the edge of a larger parent body rather than a core, E-types are all small, with only three (44 Nysa, 55 Pandora, 64 Angelina) having diameters above 50 kilometres and no others above 25 kilometers (the biggest three also orbit atypically far, c. 3 AU, from the Sun). A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2867 Šteins By Rosetta (reprocessed)
__NOTOC__ Year 867 (Roman numerals, DCCCLXVII) was a common year starting on Wednesday of the Julian calendar. Events By place Byzantine Empire * September 24 – Emperor Michael III is murdered, by order of his co-emperor Basil I. Basil becomes sole ruler (''basileus'') of the Byzantine Empire, and founds the Macedonian dynasty, Macedonian Dynasty (until 1056). Basil rebuilds the Byzantine army and navy, in an effort to restore the empire. Europe * August – Treaty of Compiègne (867), Treaty of Compiègne: King Charles the Bald cedes the Cotentin Peninsula to Salomon, King of Brittany, Salomon, duke ('king') of Duchy of Brittany, Brittany, after he had sent his son-in-law Pascweten to negotiate a peace. Charles orders the fortification of the cities of Tours, Le Mans and Compiègne. * Bořivoj I, Duke of Bohemia, Bořivoj I declares himself duke (''knyaz'') of Duchy of Bohemia, Bohemia, and founds the Přemyslid dynasty, Přemyslid Dynasty (approximate da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |